1. Field of the Invention
The present invention pertains to clamping devices. More specifically, it pertains to devices for clamping of sockets or similar socket-like components of various diameters.
2. Description of the Prior Art
Various devices are known in the prior art for clamping of a socket or socket-like component. In one type, expansible hoses are blown up, expanding the shaft for coupling with a surrounding socket. With this type of clamping shaft, problems frequently arise with sealing of the hoses.
Mechanical clamping shafts are also known which utilize expansion wedges in which the force required for expanding the wedges is afforded by a screw tool which is put onto a polyhedral which then, by a thread, shifts a connecting rod in one or the other direction. This actuation actually has the advantage that it is independent of outer energy sources as electric current or compressed air; however, in practice, problems might arise because the required clamping force must be afforded manually over the screw tool. If one does not use a very long screw tool, because of the greater lever arm which is impractible, a person often cannot afford the required clamping force, the more so as losses in transmitting the force are evident between the screw tool and the connecting rod as well as the expansion wedges.
Such mechanical clamping shafts also exist in which the drive is afforded by a pistol-cylinder-unit which is driven by compressed air. In these, the piston is frictionally connected with connecting rod and for shifting same. However, it is also problematical to afford the required clamping force, particularly with clamping shafts of smaller diameters, for instance in the order of 30 mm. The plane at disposal for the piston often is too small to afford sufficient clamping force expecially since the pressure of the compressed air also is limited, and in the workshops where such clamping shafts are being used one will not put at disposal for these clamping shafts a particular source of compressed air.